Method of treating aluminum ores.



P. J. TONE. METHOD. OF TREATING ALUMINUM OBES.

APPLICATION FILED MAB. 3, 1909. 929,5 1 '7w Patented July 27, 1909,

WITNESSES UNITED STATES ATENT oPPIoE.

FRANK J. TONE, OF NIAGARA FAL S, NEW YORK, ASSIGNOR TO- THE CARBORUNDUM COMPANY, OF NIAGARA FALLS,.NEW YORK, A CORPORATION OF PENNSYLVANIA.

METHOD OF TREATING. ALUMINUM OBES. I

Specification of Letters Patent.

Patented J'uly- 27, 1909.

To all whom it may concern:

Be it known that I, FRANK J. TONE, of Niagara. Falls, Niagara county, New York,

have invented a new and useful Method of. Treating Aluminum Ores, of which the following is a full, clear, and. exact description, reference being had to the accompanying drawings, forming part 'of this speclfication in which- The figure is a vertical section of one form of electric furnace suitable for the practice of my invention. a

In my previous patent, No. 906,172 of December 8, 1908, I have described a process for smelting aluminum: ores, in which 1' subjected to heatin an electric furnace a mixture consisting of aluminum silicate, carbon and base metalliferous material, such as iron oxid, the latter constituent being added in order to facilitate the reduction of the silicon. Underpro er conditions the products resulting from t 's firocess are pure fused alumina and silicon a 0y. I have discovered that when the base metalliferous material is added. in the form of natural emery ore, which consists usually of alumina always as sociated with impurities such as iron oxid, silica and titanium oxid, the reduction of the silica and the fusion'of the alumina are facilitated and the working of the furnace is greatly improved.

For carrying outthe process in its preferred form, the mixture is made of aluminum silicate, pulverized emery and carbon, the carbon being present in an amount sufficient to reduce all the oxids other than alumina, but insufficient to reduce the alu- 'nace, the resistance conductor being the fused charge. 1 I p In the drawing, 2 represents a receptacle, preferably made of refractory material to contain the charge, and 3, 3 are the electrode terminals connected with a source of electric current and depending into the furnace mass of mixture, 4, which is undergoing fusion, and is also in rocess of reduction.

5 represents the ished product completely fused, consisting of practically pure alumina with globules of the metallic reduction products consisting of iron, silicon andtitamum mixed and agglomerated therewith. The charge mixture 4 is supplied from time to time around and between the electrodes as the revious charge becomes reduced.

hen working with a mixture of aluminum silicate and emery, instead of aluminum. silicate and iron oxid, I attribute the improved working of'the furnace to the fact that the base metalliferous material added as emery makes the mixture very much lessconductive than the same amount of base metalliferous material added as iron oxid. The efficient working of the furnace depends upon the proper conductive relations of the charge. and the material undergoing reduction and fusion. metalliferous material to form a low silicon alloy, but an excessive amount makes the fused bath too conductive and does not permit of the operation of the process as a resistance process tothe best advantage.

The advantage in the use of emery as base metalliferous material lies in the fact that it chamber at separated points. The lower ends of the electrodes make contact with the It is desirable to have sufficient base. i

sup lies the necessary base metal to alloy cient to .fill the furnace chamber, whenthe operation is stopped and the ingot is allowed to cool. It is then broken up and crushed,

and the alumina se arated from the metallic I reduction product y concentration or other well known methods. If desired, instead of allowing the reduced metal to cool with the alumina, portions of the metallic alloy WlllCl'l een formed an ingot of fused alumina of convenient size, or sufii-' settle to the bottom of the furnace and remain in a fused 1 condition may be tapped from time to time from the furnace through a suitable tap hole as shown at 6.

I electric are it is impossible to reduce the iron My invention presents many advantages over the arc method of heating, since a more moderate heat ma be employed and the temperature is regulated so as to reduce the iron, silica and other im urities without at tacking the alumina. W en a charge of this character is submitted to the full heat of an and silica without also reducing a considerable portion of alumina; and this disadvantage is obviated by my method.

The "method is of further great advantage in that the furnace may be operated continuously with automatic and inherent regulation of the heat distribution and of the reduction and fusion zones. The treatment of the fused alumina may also be carried out in such a way as to obtain the most desirable pro erties in the finished product. p

. I e alumina whichI obtain'in this process has many valuable commercial uses. It has great hardness and abrasive qualities making 1t useful in the manufacture of "grinding wheels wh ere emery and corundum have pre-.

viously been used. It may be used forthe further manufacture of aluminum com.- pounds. It is very refractory and may be -used in fire brick, especially for basic limngs.

The iron alloys whic are formed in this process may also -be used' in the metallurgy of iron and steel.

I claim:

2. The process of treating aluminum ores,

which consists of making a mixture of aluminum silicate, emery and carbon, the amount of carbon being suflicient to reduce the silica and all compounds inthe mixture except alumina,.but insufiicient to reduce the alumina, inte osing this mixture as a resistance conductor etween electrodes, passing current through the same sufficient to fuse the alumina and reduce the other constituents to metallic form and keeping the temperature of the charge below the reduction temperature of alumina, and finall separating the alumina from the" meta ic reduction product;

substantially as described. In testimony whereof, my hand.

FRANK JQTONE.

Witnesses:

ASHMEAD G. RODGERS, AROH1E D. KYsER; 4

I have hereunto set: 

